20718589 has 4 divisors (see below), whose sum is σ = 21058300. Its totient is φ = 20378880.

The previous prime is 20718583. The next prime is 20718637. The reversal of 20718589 is 98581702.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10208025 + 10510564 = 3195^2 + 3242^2 .

It is not a de Polignac number, because 20718589 - 2⁹ = 20718077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20718583) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169764 + ... + 169885.

It is an arithmetic number, because the mean of its divisors is an integer number (5264575).

Almost surely, 2^20718589 is an apocalyptic number.

It is an amenable number.

20718589 is a deficient number, since it is larger than the sum of its proper divisors (339711).

20718589 is an equidigital number, since it uses as much as digits as its factorization.

20718589 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339710.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 20718589 is about 4551.7676786058. The cubic root of 20718589 is about 274.6545038589.

The spelling of 20718589 in words is "twenty million, seven hundred eighteen thousand, five hundred eighty-nine".